Great question! You would probably find several different answers because people would suggest the process that they are most comfortable with - not necessarily the best. Take those recommendations and go with what works for you. I'll let you know what I do and recommend...
Build a DIY scanner!! Heck yeah...its fun...and even if you don't scan a single book with it, it was still fun building it! That's what I did. (the fun building it part, not the no scanning part
). BUT...it does cost a bit. If you only have a few books to scan, it's not worth the time/money - unless you just love tinkering. If you have a lot of books to scan, then your own scanner is indeed the best way to go.
If you are going to destroy a book by cutting the spine, then cost probably isn't an issue. Just save the time and buy the ebook. Personally I could never desecrate one of my babies that way.
No need to convert to TIFF....just leave them as .jpg. 300dpi is fine for text OCR and simple images/maps. If you want a hi quality image of the cover or artwork, then scan those separately and insert them in the ePub later.
www.diybookscanner.org has some great software that will automatically collate images from two different cameras, rotate them, deskew them, and even ocr them...all for free. Getting the software set up takes a little effort but works well. I haven't used it other than test runs. I use commercial OCR software.
I personally like Abbyy.... You can get it to do the image corrections, OCR, spell check, etc. and then output to
ePub (version 10 or later). There is no reason to put in all those other formats, just to change it back to an ePub. Every time you perform an auto conversion, you will get more code that needs to be cleaned up later.
I also recommend using Sigil to do the final edits on your ePub. It lets you check/fix the html code, and do all the other stuff you need for making a clean/valid ePub automatically....and it's free. (insert prompt for donating to the Sigil developers fund here)
Cheers!